In a mine, ground support, e.g. rock bolts and screening, is used to prevent rock falls. Several different types of rock bolts may be used but all require that holes be drilled in the rock first. This is done with equipment known as rock bolters. These are mobile units with a bolting head attached. To drill a hole in the rock to install ground support, the bolting head is placed against the rock face (which is called “stinging the face”) and then a hole is drilled into the rock. The unit is then indexed to install the rock bolt as ground support.
Conventionally, the step of indexing from the drill to the bolter is problematic since it may result in misalignment of the bolter relative to the drilled hole. Conventionally, the drill feed must be retracted (by moving a feed extension cylinder or boom) to remove the drill feed from the rough uneven rock face before indexing. Ground support operations can become inefficient, time-consuming and expensive when misalignment occurs.
In an underground mine, a drift may be narrow. In a narrow drift, it may be necessary to install rock bolts which are too long to fit directly into the rock bolter or bolt driver. In these cases, the miner must install the rock bolt by hand far enough into the hole to allow the rock bolt to be connected to the drive head which is difficult and time-consuming.
A need therefore exists for an effective solution to this technical problem.